The long term goal of this line of research is to expand the development and testing of noninvasive, novel ultrasound imaging methodologies to elucidate the mechanical phenomena occurring at and near soft tissue tumor boundaries in the breast. The overall hypothesis of this work is that unique and novel axial-shear strain fill-in and contrasting margination zones created in slightly-compressed breast lesions and imaged with ultrasound axial shear strain elastography add an independent diagnostic feature to the standard BI-RADS(R)-ultrasound features, which will improve the sensitivity and specificity of noninvasive classification of benign vs. malignant breast tumors in-vivo. To test this hypothesis we propose the following: Modify existing ultrasound scanner software to provide real-time ASSE display for clinical use We will recruit participants from a pool of patients at a two hospital sites undergoing breast ultrasound evaluation of mammographically detected and/or palpable abnormalities. Those patients with lesions requiring biopsy as indicated by the standard Breast Imaging and Reporting Data System (BIRADS) criteria will be eligible for enrollment in the study. Following the conventional ultrasound exam, informed consent will be obtained. The patients will then be evaluated in a separate exam using ASSE to be performed by dedicated breast radiologists. The first 20 patients will serve as a pilot study for defining the parameters of the data acquisition protocol. We anticipate that a total of 150 patients over a one year period will be included. The presence or absence of axial-shear strain zones inside the lesion along with a high contrasting thin margin will be used as the diagnostic feature derived from the ASSEs. The ASSE feature will be evaluated by 4 trained observers, and statistical ROC analysis of these results will be performed. Ultrasound guided core needle biopsy or surgical excision will serve as the pathological benchmark. PUBLIC HEALTH RELEVANCE: The research we propose in this application is aimed at testing a novel ultrasound technology based on a new contrast mechanism for breast tumor classification. Once developed, these methodologies could become important for (1) improving tumor margin visualization for diagnosis and treatment, and (2) for differentiation between benign fibroadenomas and other benign pathologies, and malignant carcinomas in the breast in vivo, based on their unique elastographic axial-shear strain signatures. This novel technology may provide powerful tool that complement and overcome some of the limitations of existing ultrasound imaging techniques while maintaining the advantages of low costs, and high safety and accessibility typical of ultrasound-based modalities.